A magical star looking thing at a football game, right before 2 undeafeted teams played!

I was at a football game, one was ended, and one was just beginning. The previous team was having a meeting sitting down, right underneath the craft, although it was high. The craft sort of resembled a star, although the odd thing was there was a white triangular shadow underneath it.

By the time I had noticed it, several other people were looking up at it, including about a third of the football team. About 20 seconds later, it slowly faded away. Ironically, when all the people were looking up at it, I was getting out my camera, and as soon as I turned it on, it had began to fade away.

The craft was a bit higher than a normal plane would be, although the shadow stretched far down, but not nearly far enough to reach the ground.